The basic theory and operation of thermoelectric devices has been developed for many years. Presently available thermoelectric devices used for cooling typically include an array of thermocouples that operate in accordance with the Peltier effect. Thermoelectric devices may also be used for heating, power generation and temperature sensing.
Thermoelectric devices may be described as essentially small heat pumps that follow the laws of thermodynamics in the same manner as mechanical heat pumps, refrigerators, or any other apparatus that is used to transfer heat energy. A principal difference is that thermoelectric devices function with solid state electrical components (thermoelectric elements or thermocouples) as compared to more traditional mechanical/fluid heating and cooling components.
Certain locations may not have access to electrical power grids, but may include heat differentials. Current power generation techniques in such locations are ineffective. Some require modification of structures (e.g., pipes carrying a hot or cool medium) in order to generate power.